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Procedural 3D Perlin noise terrain generation

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This commit is contained in:
KonstantinosSykas 2017-10-02 20:42:59 +03:00
parent 3594e7e455
commit 538a0d6583
1 changed files with 2 additions and 16 deletions
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18
src/Core/Materials/OOPlanetTextureGenerator.m
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@ -953,31 +953,17 @@ static float SampleNoise3D(OOPlanetTextureGeneratorInfo *info, Vector p)
}
/* Generate shuffled permutation order - each value from 0 to
kPermutationCount - 1 occurs exactly once. This shuffling provides all the
randomness in the resulting noise. Don't worry, though - for
kPermutationCount = 1024 this allows for 4e2567 different noise maps,
which is a lot more than RanRot will actually give us.
*/
// Noise map generator
static BOOL MakePermutationTable(OOPlanetTextureGeneratorInfo *info)
{
uint16_t *perms = malloc(sizeof *info->permutations * kPermutationCount);
if (EXPECT_NOT(perms == NULL)) return NO;
/* Fisher-Yates/Durstenfeld/Knuth shuffle, "inside-out" variant.
Based on pseudocode from http://en.wikipedia.org/wiki/Fisher-Yates_shuffle
When comparing to the pseudocode, note that it generates a one-based
series, but this version generates a zero-based series.
*/
perms[0] = 0;
uint16_t *curr = perms;
uint16_t n;
for (n = 1; n < kPermutationCount; n++)
{
uint16_t j = RanrotWithSeed(&info->seed) & kPermutationMask;
*++curr = perms[j];
perms[j] = n - 1;
perms[n] = RanrotWithSeed(&info->seed) & kPermutationMask;
}
info->permutations = perms;